1. The Field of the Invention
The present invention relates generally to optoelectronic devices. More specifically, the present invention relates to optoelectronic devices that use microcode to account for temperature and current effects as well as other diagnostic parameters to determine the laser power for optoelectronic devices.
2. The Related Technology
Computing and networking technology have transformed our world. As the amount of information communicated over networks has increased, high speed transmission has become ever more critical. Many high speed data transmission networks rely on optical transceivers and similar devices for facilitating transmission and reception of digital data embodied in the form of optical signals over optical fibers. Optical networks are thus found in a wide variety of high speed applications ranging from modest Local Area Networks (“LANs”) to backbones that define a large portion of the infrastructure of the Internet.
Typically, data transmission in such networks is implemented by way of an optical transmitter (also referred to as an “optoelectronic transducer”), such as a laser or Light Emitting Diode (“LED”). The optoelectronic transducer emits light when current is passed through it, the intensity of the emitted light being a function of the magnitude of the current. Data reception is generally implemented by way of an optical receiver (also referred to as an optoelectronic transducer), an example of which is a photodiode. The optoelectronic transducer receives light and generates a current, the magnitude of the generated current being a function of the intensity of the received light.
Various other components are also employed by the optical transceiver to aid in the control of the optical transmit and receive components, as well as the processing of various data and other signals. For example, such optical transceivers typically include a driver (referred to as a “laser driver” when used to drive a laser signal) configured to control the operation of the optical transmitter in response to various control inputs. The optical transceiver also generally includes an amplifier (referred to as a “post-amplifier”) configured to amplify the channel-attenuated received signal prior to further processing. A controller circuit (hereinafter referred to as the “controller”) controls the operation of the laser driver and post-amplifier.
Within an optical transceiver module, laser power, i.e., the amount of light emitted from the laser, is typically difficult to measure directly. Instead, laser power is often calculated indirectly by placing a photodiode near a laser and measuring the amount of residual light being transmitted from the laser. The photodiode produces a current that corresponds with the amount of light emitted, or laser power, from the laser.
During transceiver operation, various factors can affect the measurement of laser power as described above. For instance, variations in transceiver temperature can skew the measurement of residual light from the laser by the photodiode. In addition, voltage changes across the photodiode can alter laser power photodiode measurements.
Conventional systems and methods for measuring and calculating laser power have been unable to adequately compensate for temperature, voltage, and other factors that affect the accuracy of laser power and other monitored parameters. It would therefore be useful to provide a manner by which improved accuracy can be obtained in laser power and other parameter measurements in an optoelectronic device, such as an optical transceiver, and to compensate for factors that may affect such parameter measurements.